Telephone system



July27, 1937, o. MYERS 2,088,305

v TELEPHONE SYSTEM l Filed March 1l, 1936 2 Sheets-Sheet 2 /NVE/WOR O. MYERS Byam Patented July 27, 1937 UNITED STATES PATENT CFFICE Telephone Laboratories,

Incorporated, New

York, N. Y., a. corporation of New York Application March 11, 1936, Serial No. 68,259

7 Claims.

This application relates to telephone systems and has for its object to increase the reliability of such systems. In telephone systems there are numerous instances in which a relay associated 5 with the talking circuit is operated from common apparatus to control certain functions. In some cases if .this relay fails to operate, the wrong party may be signaled or charged, while in other cases the entire connection may fail. In addition, in the cross-bar system in particular, the timing and alarm equipment is associated with the common control apparatus and it is especially desirable that the switching functions be completed properly before the common apparatus is released.

In accordance with the present invention, means is provided for indicating when a relay is fully operated. More specifically this indicating means comprises a double-wound polarized relay so arranged that when both windings are ener- 20 gized, the relay armatures remain on their back contacts. The relay to be operated is connected to the two windings in parallel, thereby shunting the releasing winding and permitting the polarized relay to operate. The connected relay may 25 either operate at once or be operated by a subsequent reduction of the resistance in series with the operating winding of the polarized relay. When the connected relay operates, it closes a characteristic potential to its operating circuit 30 which may conveniently be ground, this potential shunting the operating winding of the polarized relay and permitting the releasing winding to become effective to open the contact of the polarized relay. The successful operation and release of the polarized relay controls an indicating means which may serve to advance the operation of the control apparatus or may cause it to. release.

The invention will be more clearly understood from a consideration of the following description 40 in connection with the drawings, in which Fig. 1 shows a simplified embodiment of the invention, and Figs. 2 and 3 show its application to actual working circuits.

Referring rst to Fig. l, when the equipment of which polarized relay is a part is seized, the relay is included in a circuit from battery, through its windings to ground through resistance |02.

Under this condition, the relay remains released, with its back contact closed. When the equipment at the right of the dotted line is connected to the equipment at the left of the dotted line, relay |0| is connected to the two windings of relay |00 in parallel over conductor |05. This shunts the lower releasing winding of relay |00,

permitting the polarized relay to operate and close a circuit for relay |03, which locks independent of relay |00. When it is desired to operate relay- |05, direct ground (or low resistance ground) is connected in shunt of resistance |02, 5 operating relay lill. Relay l0! in turn locks and 1 extends its locking ground in shunt of the upper operating winding of relay |00 which permits the releasing winding to become effective and restore the armature to its back contact. A circuit is now closed over the back contact of relay |00, front contact of relay |03, to the winding of relay E00 to indicate that relay |0| has operated and locked. If relay i0!! fails to lock, relay |00 remains operated, relay 00 fails to operate and the 15 time alarm indicates a trouble condition.

Relay 00 also serves to test conductor |05 which connects relays |05 and |00 for unstandard conditions. If the conductor is open, relay |00 cannot operate and the failure to operate relay llld would cause the time alarm to function. Similarly, if a false ground were present, the lower winding of relay E00 would be energized to hold the armature on its back contact and relay |011 would bring in the alarm.

Such an arrangement could well be applied to setting the ringing control relays in the incoming junctor from the marker.

This arrangement also may be applied to the establishment and testing of a connection similar to the functions performed by the decoder marker in the application of W. W. Carpenter, Serial No. 27,305, led June 19, 1935.

The connection between a calling district junctor and an outgoing trunk includes a primary district selector 200, a district link 20|, a secondary district selector 202, an office junctor 203, a primary oiice selector 204, an ofce link 205 and a secondary oii'ce selector 206. Access from the marker decoder to the wanted trunk is obtained by means of an office frame connector 201 which includes several multicontact relays operated by the marker in accordance with the registered designation. Access is then obtained to the calling district junctor by means of a district 4,5 frame connector 208, including multicontact relays individual to the marker decoder and to the district junctor. As a result, relay 30| is operated and locked under the control of relays 302, 303 and 304.

During the registration of the oflice code in the decoder marker relay 305 is operated, connecting battery to the left windings of relays 306, 301 and 302 and ground to the right windings of these 55 relays. Under this condition these relays hold their back contacts closed.

When the channels between the district junctor and trunk have been tested and an idle one selected, relay 308 operates, closing two test circuits. One extends from the hold magnet 2|0 of the primary district selector 2M? through the district frame connector 203, inner left contact of relay 308, right back contact of relay 303, third right contact of relay 30l, to the junction of the windings of relay 306. The other extends from the hold magnet 2 l0 of the secondary oiilce selector 2li, right contact of relay 308, right back contact of relay 399 to the junction of the windings of relay 301.

Relays 30B and 30T will operate only when encountering battery through the hold magnets. If the corresponding leads are open or grounded relay 303 and `301 will not operate. The magnets operate in series with the right windings of the test relays.

Relay 3|0 was previously operated and locked over back contacts of relays 305 and 301 to ground at the inner left contact of relay 305. If both relay illll and relay 331 operate relay 3|0 releases. With relay (H released, a circuit is closed from battery through the windings of hold magnets 2|2 and 2M serving the secondary district selector and primary office selector respectively, through the district frame connector, outer left contact of relay 3M, outer left back contact of relay 3l0, back contact of relay 3||, over the normal contacts of either relay 309 or 303 to ground at the outer right contact of relay 30|. This ground causes the operation of magnets 2|2 and 2M, which extend their operating ground over the sleeve contacts oi the switches to the district link and office link respectively. This ground holds magnets 2|0 and 2|6 operated but shunts the operating windings of relays 306 and 301, causing them to reclose their back contacts provided switches 202 and 204 have operated properly. With magnet 2|0 already operated, this ground is extended over the primary district selector through the district frame connector 203, inner left back contact of relay 3l0, back contact oi relay 397. outer right back contact of relay 350 to the winding of relay 308 and battery. It the primary district selector operates properly relay 303 also operates. Similarly ground on the sleeve of the oiiice link is extended, if the secondary oiiice selector has closed satisfactorily, over the sleeve contact of that switch, through the office frame connector 201, middle left back contact of relay 3l0, back contact of relay 306, inner right back contact of relay 3|0 to the winding oi' relay 303 and battery, operating relay 303. With relays 309 and 363 operated, the ground from relay 30| is disconnected from the oice junctor, leaving it connected to battery and ground through the windings of relay 302. Relays 303 and 309 connect ground from relay 30| over their alternate contacts to the windings of relays 306 and 301 respectively to hold the latter relays in their non-operated position.

Ground through the right winding of relay 302 is suicient to hold magnets 2|0, 2|2, 2|4 and 2|6 operated, as well as relays 309 and 303. Relay 302 now operates provided there is no false ground on the holding magnet circuit caused by a double connection.

The release of relay 3|0 permitted relay 304 to operate opening one locking circuit of relay 30| and the operating circuit of relay 3||. Relay 303 opens a second locking circuit of relay 30| and relay Sill. opens the third, permitting relay 30| to release.

Switch 236 in operating, connects ground to conductor 2li? to mark the trunl; busy and this ground is extended through the cnice frame connector and over the iront contact of relay 309 to the winding ci relay Relay 30| causes the release of relay in the district junctor which connects ground to the sleeve oi the primary district selector to hold the hold magnets operated. This ground shunts the operating winding of relay which releases if the holding ground is properly applied.

With relays and released and relay 3|2 operated ground is connected to conductor 3|3 to release the marker from the switches.

A somewhat similar arrangement may be used in testing the terminating end of a connection.

What is claimed is:

l. In a telephone system, a conductor, a relay connected to one end of said conductor, means to operate said relay over said conductor, means to connect a characteristic potential to said conductor responsive to the operation oi said relay, and means connected to the other end of said conductor responsive to the connection -o said relay to said conductor and the subsequent connection of said characteristic potential to said conductor to indicate that said relay has operated, correctly.

2. In a telephone system, a conductor, a relay, means to operate said relay over said conductor, means to connect a characteristic potential to said conductor responsive to the operation of said relay, and means connected to said conductor responsive to the connection oi said relay to l said conductor and the subsequent connection of said characteristic potential to said conductor to indicate that the relay has operated correctly, said means comprising a double-wound polarized relay, so connected as to operate in response to a connection with said first relay and released in response to said characteristic potential.

3. In a telephone system, a relay, and means to indicate the operation of said relay, comprising a double-wound polarized relay, means to connect said polarized relay with said first relay to operate said relays, means responsive to the operation of said rst relay `to release said polarized relay and indicating means controlled by said polarized relay.

4. In a telephone system, a relay, and means to indicate the operation of said relay, comprising a double-wound polarized relay, means to connect one winding of said polarized relay with said rst relay to operate said relays, means responsive to the operation of said first relay to hold said first relay operated and to shunt said winding of said polarized relay, and indicating means controlled by said polarized relay.

5. In a telephone system, a relay, and means to indicate the operation of said relay, comprising a double-wound polarized relay, means for energizing the windings of said polarized relay to hold said relay unoperated, means to connect said rst relay to the windings of said polarized relay. shunting one winding to permit said polarized relay to operate, means to reduce the resistance in circuit with the other winding of said polarized relay to operate said rst relay, means responsive to the operation or" said iirst relay to shunt said other winding of said polarized relay releasing said relay, and means responsive to the operation and release of said polarized relay to indicate that said first relay has operated properly.

6. In a telephone system, a relay, and means to indicate the operation of said relay comprising a polarized relay having an operating Winding and a releasing winding, means to energize both windings of said relay, means to connect said rst relay to the windings of said polarized relay to render said operating Winding effective,

l0 means to reduce the resistance in circuit with the operating winding of said polarized relay to operate said iirst relay, means responsive to the operation of said rst relay to render said releasing Winding effective, and means responsive l5 to the operation and release of said polarized relay to indicate that said rst relay has operated properly.

7. In a telephone system, a conductor, a relay, means to operate said relay over said conductor, means to connect a characteristic potential to said conductor responsive to the operation of said relay, means connected to said conductor responsive to the connection of said relay to said conductor and the subsequent connection of said characteristic potential to said conductor to indicate that said relay has operated correctly, and means to prevent the operation of said indicating means in response to the premature presence of said characteristic potential on said conductor.

OSCAR MYERS. 

